FBN1 and mitral valve disorder: Of those, a novel FBN1 deletion encompassing exons 1-5 (Figure 1, Panel A) was identified in a 27-year-old male (patient 1; Tables 1 and 2) with dilated aortic root (3.99 cm, z-score of 3.76), mild tricuspid and mitral valve prolapse, tricuspid valve insufficiency, height 201 cm (6' 8") arm span 205.5 cm (6'10"), arachnodactyly, joint hypermobility, positive thumb and wrist signs, combined pectus carinatum/excavatum deformity of the anterior chest wall, and marked diffuse striae over the lower back and hips.